Clerics who have been critical of the brutal crackdown that followed Iran's 2009 presidential election are coming under fresh pressure from the Iranian establishment, judging by a wave of recent attacks.

The incidents have all come since the one-year anniversary of the June 12 vote, which sparked unprecedented street protests in the Islamic republic and allegations of massive fraud.

On June 13, hard-liners in the holy city of Qom attacked the vehicle of opposition leader Mehdi Karrubi and surrounded the house of senior reformist cleric Grand Ayatollah Yusuf Sanei, whom Karrubi was visiting. Vandals later ransacked Sanei's offices as well as those of the late Ayatollah Ali Montazeri -- regarded as the "spiritual father of the Green Movement" whose sons have continued to challenge authorities.

WATCH: YouTube video of the attack on Montazeri's office:

The language that the attackers were using was particularly incendiary. One of the perpetrators referred to Sanei as "the American source of emulation," a play on the status that is granted to the most influential clerics. The grandson of revolutionary Ayatollah Ruhollah Khomeini, Seyed Hassan Khomeini -- who has been supportive of the Green Movement -- was meanwhile dismissed as unworthy of his pedigree. In another video, "Karrubi and his kind" were warned about speaking against "the Iranian establishment, Islam, and revolutionary values." They also called on Iranian leaders and officials to make sure that Qom gets rid of "these dirty people."

At one point in another video, one of the hard-liners in front of Sanei's home was heard to shout, "We demand from the authorities to get rid of these houses soon. These sources of corruption allow these dirty people to have a place and base here."

A few hours later, in the early hours of June 14, Montazeri's office was sealed on the orders of Iran's Special Court for the Clergy. Montazeri's sons had reportedly come under pressure to shut down the office of their father, whose memorial services provided a platform for opposition gatherings despite official threats (and an attack on Sanei's home).

Taking On Clerics

After Montazeri's office was sealed, his son Ahmad Montazeri told RFE/RL's Radio Farda that the government's desire is to erase his name from history.

Some observers say the attacks are aimed at sending a message to other Iranian clerics who have been critical of the postelection crackdown and related government actions.

"[Authorities] think that if they attack the house of a senior cleric, it will create fear among the lower-rank clerics," Mojtaba Vahedi, a former editor of the reformist daily "Aftabe Yazd," who currently resides in the United States, told Radio Farda. "If they attack the house of a senior politician, politicians without any support will become scared. If they beat up a couple in the streets, it will intimidate young people from taking to the streets to protest. All the current establishment does is aimed at creating fear, and yet all the violence hasn't brought any result."

The hard-liners who launched the attacks were not acting independently, according to Hossein Karrubi, the son of the opposition leader. He told the Jaras website that the sudden nature of the gathering and the manner of the attack indicate they were acting on orders from above.

Another of Montazeri's sons, Said Montazeri, hinted at who he thinks was ultimately behind the attacks when he said they followed Supreme Leader Ayatollah Ali Khamenei's June 12 trip to Qom. "Thanks to Khamenei, Qom's atmosphere became convulsive," Montazeri said.

Hassan Shariatmadari, a Germany-based political analyst and son of Grand Ayatollah Kazem Shariatmadari -- himself an influential Iranian cleric who was placed under house arrest in the 1980s -- tells RFE/RL that the attacks are unlikely to have happened without Khamenei's consent.

"A closed circle of the commanders of the Revolutionary Guards and Khamenei make joint decisions regarding these issues," Shariatmadari says. "Khamenei can either prevent it or encourage it; unfortunately, he encourages [such actions]."

Qom Before The Storm

Only a few senior clerics in Qom congratulated President Mahmud Ahmadinejad after his disputed reelection last year, and many reportedly refused to endorse him.

Shariatmadari says the attacks can be seen as part of an intimidation campaign launched by the Iranian government to silence dissenting voices, including those of clerics in Qom who have not sided with the government.

"Following the anniversary of last year's June 12 vote," Shariatmadari says, "the ruling faction wants to show its muscle and say, 'We will keep pressuring the Green Movement, and the independent clerics should cut all their ties with [opposition leaders] Mir Hossein Musavi and Mehdi Karrubi.'"

Shariatmadari believes the attacks against reformist clerics could backfire, however, and lead to condemnations and protests by other clerics.

The attacks on the offices of Sanei and Montazeri followed by around two weeks an abortive speech by the grandson of the founding father of the Islamic republic. Hassan Khomeini was heckled and ultimately prevented from speaking at a ceremony marking the 21st anniversary of the death of his grandfather, Ruhollah Khomeini, known to many Iranians simply as "the Imam." A number of clerics and political figures -- including Sanei, Karrubi, and Musavi -- condemned the incident.

In a June 14 statement posted on the Kaleme website, Musavi said the attacks on the offices of the grand ayatollahs and the pressure against them "only destroys the legitimacy of the Iranian establishment."

Musavi ended his statement with a reference to Khomeini's arrest in 1963 -- which led to public demonstrations and the Movement of 15 Khordad -- asking Iran's current leaders: "Have you forgotten that the attack against the house of the Imam led to the removal of the pillars of the dictatorship on [June 5, 1963] and then in [February 1979]? And haven't you learned your lesson?"

Radio Farda broadcaster Alireza Kermani contributed to this report

Golnaz Esfandiari

Golnaz Esfandiari is a senior correspondent with Radio Free Europe/Radio Liberty. She can be reached at EsfandiariG@rferl.org